Lamp and receptacle therefor



Dec. 28, 1943. ARgTAN 2,337,745

LAMP AND RECEPTACLE THEREFOR Filed July 26, 1941 v I 4 3X Z INVENTOR. 7 WALL/AM n1 6/9/FfM/V6 JTTOKA EK Patented Dec. 28, 1943 UNITED STATES PATENT OFFICE.

LAMP AND RECEPTACLE THEREFOR William W. Garstang, Indianapolis, Ind., assignor to Electronic Laboratories, Incorporated, Indianapolis, Ind., a corporation of Indiana Application July 26, 1941, Serial No. 404,145

Claims. (Cl. 2408.16)

the cockpit no apparent source of light. It has been found that light rays which would ordinarily not only illuminate the instruments but also illuminate the cockpit have a tendency to distort the-pilots vision during night flying and after he has been looking into darkness ahead for a considerable length of time. As a result of this condition, there has been developed a socalled black light through the medium of which the instrument indicators, which have been colored with a fluorescent material, may be illuminated by ultra-violet or near ultra-violet rays developed by a lamp which ultra-violet or near ultra-violet rays are not visible to the eye.

The present invention relates to a lamp having the above characteristics.

It has for one of its objects that of providing a compact lamp and lamp structure capable of emitting ultra-violet or near ultra-violet rays and provided with means for controlling the intensity of these rays.

For the purpose of disclosing the invention, certain embodiments thereof are illustrated in the accompanying drawing, in which.

Fig. 1 is a longitudinal section of a casing embodying my invention;

Fig. 2 is a longitudinal sectional view of the lamp bulb adapted to be fitted within said casing;

Fig. 3 is aside elevation of an intensity control shield adapted to surround the lamp illustrated in Fig. 2, the two then beingcapable of assembly in the structure illustrated in Fig. l;

a Fig. 4 is a modification of a lamp tube adapted for use in the structure illustrated in Fig. 1;

Fig. 5 is a longitudinal sectional view of a modification of my invention;

Fig. 6 is a longitudinal view of thestructure illustrated in Fig. 5; and

Fig. 7 isan elevation of the intensity controlling shutter.

Referring first to the structures illustrated in Figs. 1, 2 and 3, there is provided a tubular casing I which may be formed of metal, preferably bee ing formed of aluminum, for lightness. This tubular casing l is provided on one side with a cutout section or opening 2 which provides a view opening in the casing. Mounted within the casing I, at one end,'.is a hollow plug 3 which telescopes the end of the casing and makes a snug fit therein. This plug is provided with a hollow stem 4 screwthreaded on its exterior as at 5 to receive a supporting bracket 6 and the clamping nuts I and 8 for maintaining the bracket in position The interior of the stem 4 is provided with an insulating bushing 9 and within this bushing is fitted a contact plug l0 having a spring contact ll capable of making engagement with the conducting contact plug of the conducting wire and provided at its opposite end with a contact l2. The opposite end of the casing l is split longitudinally as at 13 to provide a series of spring fingers adapted to surround the cylindrical portion l 4 of a rotatable cap'having a closed end l5. This cap is provided with an annular groove I6 capable of receiving an annular bead IT in the spring fingers formed at the end of the casing whereby when the cap is telescoped in po sition, it will be held against longitudinal displacement while permitting rotation thereof.

Removably mounted within the casing l is a secondary casing l8 formed'of insulating material and having its ends closed-by end caps l9 and 20. Contact studs 2| and. 22 extend through these end caps, the stud 22 being adapted to con tact the contact I2 and the stud 2| being adapted to make an electrical contact with the interior of the closure cap rotatably mounted on the casing, which casing may be grounded. This tubular member likewise is provided with an elongated slot or view opening 23 in one portion thereof and with a series of view openings 2424 grad-- ually diminishing in size.

Mounted within the casing I8 is a lamp comprising a bulb 25 with insulating end sleeves 26 and 21 and mounted within the end sleeve 21 is a starting switch 28. This lamp bulb 25 is of the fluorescent tube type. The glass of the bulb,

however, is formed of material which, while permitting the passage therethrough of ultra-violet or near ultra-violet rays is impervious to the passage of visible light rays.

If desired, the interior of the glass bulb may be coated with a fluorescent material capable of regenerating the ultra-violet rays developed by the lamp and converting these ultra-violet rays into visible and near ultra-violet rays which near ultra-violet rays are invisible to the eye. How'- ever, due to the characteristic of the glass of which the bulb is formed, the near ultra-violet rays will be passed therethrough. The lamp bulb contains the usual quantity of mercury and the usual heaters 29--29 for heating or ionizing the mercury for the provision of a mercury arc to develop the ultra-violet rays. At each end of the lamp bulb. there is provided a pair of contacts, one of which at one end is connected with the contact 22 and the other of which, at the same end, is connected through .a uitable conductor 30 with one terminal of the starter switch. The opposite terminal of this starter switch is connected to one contact, at the opposite end of the bulb and the other contact at the same end is connected to the terminal 2!.

This bulb, as is illustrated in Fig. 2, is mounted within and rotatable with the insulating casing l8 which is preferably formed of material im pervious to the passage of any light rays. This casing is provded with 2. lug l8 adapted to fit within an elongated slot 3! in the sleeve portion Id of the cap so that the entire casing is capable of rotation with this cap. The contact M, as before stated, makes contact with the cap and through the cap and casing i is grounded for the completion of the lamp circuit.

The above described structure thus provides a compact readily controlled lamp structure having means for readily controlling the intensity of the light rays developed thereby. It is obvious that when the slot 23 in the casing i8 coincides with the slot 2 in the casing i, a maximum passage of the near ultra-violet rays developed by the lamp is permitted. For changing the intensity of the rays emitted by the lamp, the casing it may be rotated through the medium of the rotatable cap to cause the openings 25, of various sizes, to coincide with the slot 2 in the cas- -In this structure, the lamp bulb 25 may be coated with a material impervious to the passage of light rays of any character. Certain portions, however, of the lamp bulb may be left clear of this material so that the passage slot 25' of maximum area may be provided and other portions left clear as at 25" in the form of rows of openings of varying diameters to permit control of the intensity of the light rays, by the rotation of the bulb.

In Figs. 5, 6 and 7, there is illustrated a modification of the structure illustrated in Figs. 1, 2 and 3. 'In this structure, there is provided a cylindrical casing 32 having the elongated slotted opening 33. Within this casing is an end contact clip 34 and side contact clips 35,- suitably insulated from one another by insulating material 36 and adapted to receive one end of a lamp having the same characteristics as the lamp bulb 25 with the exception that one contact of the lamp is a cylindrical cap 3'! while the opposite contact is a pin 38. The opposite end of the casing is likewise provided with a side contact clip 39 adapted to embrace the opposite cap of the lamp and with an end contact clip 40 connected .bya conductor M with the contact plug 42. This contact plug isfitted within and insulated from a metallic end closure 33 having a threaded stem 44 similar to the stem *4. In this lamp structure. a manually controlled tarting switch .45 is provided. Surrounding the cylindrical casing 32 is a shutter casing 32 provided with a knurled end cap 46 and having a plurality of elongated slots. 'Ifhe' elongated slot 377 has substantially the same area as the longated slot 33 in the casing, while the elongated slots 68, 6Q, etc., gradually narrow so that as the shutter is rotated, a maximum amount of rays controllable to'practically a minimum by the rotation of the shutter is permitted.

I claim as my invention: 7

l. A lamp structure comprising in combination, a cylindrical casing having an elongated opening in the wall thereof, a contact terminal at one end of said casing, a removeable, rotatable cap for the open end of said casing and a self-com tained unitary lamp unit rotatable in said cas ing, said unit comprising an enclosing cylindrical shell impervious to the passage of light and having a light emitting opening in the wall thereof, a fluorescent lamp bulb mounted within said shell, an insulating plug at each end of said shell and a contact. terminal mounted on each of said plugs respectively connected with a terminal-of said lamp, oneof said cantact terminals having a separable connection with the contact terminal in said casing and a separable driving connection between said unit and said cap to permit the rotation of said unit by said cap for moving the light emitting opening in said shell into or out of coincidence with the opening in the wall of said casing.

2. A lamp structure comprising in combination, a cylindrical casing having an elongated opening in the wall thereof, a contact terminal mounted at one end of said casing, a removeable rotatable cap for the open end of said casing and a selfcontained unitary lamp unit rotatably mounted in said casing, said unit comprising an enclosing cylindrical shell impervious to the passage of light and having a light emitting opening in the wall thereof, a fluorescent light bulb mounted within said shell, an insulating plug at each end of said shell and a contact terminal mounted on each of said plugs and connected with terminals of said lamp, one of the terminals on one of said plugs having a separable connection with the contact terminal in said casing and a separable driving connection between said cap and said unit to rotate said unit by said cap, to move the opening in said shell into or out of coincidence with the opening in said casing.

3. A lamp structure comprising a cylindrical casing having an elongated opening in the wall thereof, a contact terminal at one end of said casing, a removeable rotatable cap for the open end of said casing and a self-contained unitary lamp unit rotatably mounted in said casing, said unit comprising an enclosing cylindrical shell impervious to the passage of light and having a light emitting opening in the wall thereof, a fluorescent lamp bulb capable of transmitting ultra violet or near ultra-violet light only mounted within said shell, an insulating plug at each end of each shell having a contact terminal mounted thereon, one of said contact terminals having a separable connection with the contact terminal in said casing and a separable driving connection between said unit and said cap for rotating said unit by said cap to move the light emitting opening in said shell into or out of coincidence with the opening in said casing.

4. A lamp structure comprising in combination, a cylindrical casing having an elongated opening in the wall thereof, a contact terminal at one 'end of said casing, a removeable rotatable cap for the open end of said casing and a selfassures contained unitary unit rotatably mounted in said casing, said unit comprising'an enclosing cylindrical shell impervious to the passage of light and having a light emitting opening in the wall thereof, a fluorescent lamp bulb capable or transmitting ultra violet or near ultra violet light only mounted within said shell, a starting switch for said lamp mounted within said shell and connected with terminals of said lamp, an insulating plug at each end of said shell each having a contact terminal connected to a terminal of said lamp, one of said shell terminals having a separable connection with the vcontact terminal of said casing and a separable driving connection between said cap and said unit for rotating said unit to move the light emitting openings thereof into or out of coincidence with the opening in said casing.

5. A lamp structure comprising in combination, a cylindrical casing having an elongated opening in the wallthereof, a contact terminal mounted at one end obs-aid casing, a removeable rotatable cap for the open end of said casing and a self-contained unitary lamp unit rotatably mounted in said casing, said unit comprising an,

at each end of said shell, 9, contact terminal.

mounted on each of said plugs and connected with the lamp terminals, one of said plug terminals having a separable connection with the contact plug in said casing and a separable driving connection between said unit and said cap for rotating said unit by said cap to place the various openings in said shell into or out of coincidence with the opening of said shell.

, WILLIAM w. GARSTANG. 

